The higher the voltage of an electric cordless tool the more power it will generally have. There is a tradeoff between weight and power so be sure you weigh your needs against the power of the tool you buy.

Stationary compressors are designed to be bolted in a fixed area and wired directly to a building's electrical circuit, these are ideal for garages and workshops. Portable air compressors are perfect for jobs that require use of air tools like nail guns frequently, such as re-siding your home or building a deck. Pancake compressors are smaller and very easily portable, they're great for inflating and running small tools. Twin tank compressors can store more air so they don't have to run as often.

A larger tank size is typically means you can get a longer use out of your air compressor at one time. If you are using tools that require a high volume of air for continuous use then you will need a larger tank. But for sporadic use and tools that only require quick bursts of air you will will likely be fine with a smaller tank.

Single-stage compressors have one piston that compresses and delivers air to the storage tank. They are suitable for most home users. Two-stage compressors have two pistons that compress and deliver air to the tank. These can store more air in the same space as a single-stage and are much better for commercial uses and shop environments.